Radiation exposure during medical procedures requiring x-rays or other ionizing radiation is a major health concern for health care workers (HCW). Procedures requiring real-time imaging, such as percutaneous procedures, involve a patient on a table with an x-ray device mounted on a C-arm, known as an x-ray gantry. The radiation is emitted from a “tube” on the bottom of the C-arm and is directed upward through the bottom of the table and the patient. The physician and other attending HCWs are typically standing next to the table attending the patient and are subject to the radiation.
Most of the radiation exposure to the HCWs emanate from x-ray photons that are reflected off of the patient's bones and other structures during the procedures. More specifically, the exposure to the HCWs from their waists down result from x-rays coming directly from the tube, as well as reflecting off of the table structure and the bones of the patient. Exposure to the HCWs from their waists up result from X-rays reflecting off of the bones of the patient and structures above the patient.
Most are composed of an x-ray blocking material in the form of a hard, planar shield. These are attached to the ceiling or x-ray table. Some are flexible and some are clear. They are cumbersome, do not conform to the patient's anatomy (reducing effectiveness in blocking x-rays), do not facilitate surgical access to the body, and do not provide storage for tools or lighting.
Additionally, these shields are heavy and often get in the way of adequate fluoroscopic visualization of the patient or key areas of the patient that require easy access or monitoring. The HCW has to move these heavy shields manually and also conform their bodies to visualize around the impediments caused by the existing devices. This is a major cause for musculoskeletal morbidity of the HCW resulting in chronic neck, back injuries. Consequently, it is common for the HCW to sacrifice radiation protection for better visualization as well as better ergonomics by moving the current shields out of the way or positioning them in a markedly sub-optimal protection position. Finally, it is not uncommon that the HCW forgets to move the shields for adequate protection.
Other x-ray blocking shields have consisted of draping x-ray absorbing material (DXAM) over the patient during procedures. Because these draped materials lay on the patient, they need to be covered with sterile material or be disposed of after every use. This is cumbersome and, as a result, most of the draped material is made as a disposable item (disposable drape and x-ray barrier inside), increasing cost and toxic waste. Moreover, the draped polymer is heavy and uncomfortable for the patient because the patient supports the weight. Additionally, because the DXAM is positioned under the sterile drape that covers the patient, it is difficult to remove during the procedure should an emergency arise that requires more x-ray visualization.
Another problem in protecting personnel from scatter x-ray exposure during medical procedures is that, when the x-ray source is below the patient, the x-ray is scattered off of the patient toward the floor. As a result, the legs and feet of personnel are heavily exposed to ionizing radiation. In addition, the x-ray tube housing can often leak substantial x-radiation, often of high energy. This also increases personnel exposure to high energy ionizing radiation.
Current shielding for “below-the-table” radiation consists primarily of a radiation blocking barrier (called the table skirt) that hangs from the table. Since the table height is varied during the procedure, there is often a gap between the floor and the barrier. Additionally, these table skirts are usually hung on a lever arm from the foot end of the x-ray table. They do not cover the gap between the table and the floor from the mid abdomen to the head. As a result, personnel in the room stationed at the patient's head or side receive substantial radiation exposure. This is a particular risk for physicians performing procedures that require manipulation of catheters near the patient's head (such as subclavian or jugular vein access, subclavian artery access, or transesophageal ultrasound imaging).